Hello, I am over in the UK and have a history of autoimmune diseases. I have 8 so far, mostly not serious, including Alopecia, celiac, asthma, B12 deficiency etc and more interestingly addisons disease. I am 47 year old female and never present properly and usually have a hard time getting diagnosed. The delay in getting my Addisons's disease diagnosed nearly killed me as the consultants just would not accept evidence as one blood test was not conclusive as one of my medications was skewing the results and the consultants would not accept this.

Anyway eventually I was diagnosed, after I wrote a 27 page paper and found someone who would redo the tests whilst I stopped the 'offending' drug, and hoped that everything would start to look up. Sadly over the summer in very hot weather I got extreme muscle weakness - I was unable to hold my head up, use my arms and my eyes kept closing and eyelids drooped. With any stress or tiredness things would be worse and I could get stuck and need 3 other adults to move me as I could not get legs to move or keep my body up.

My gp thought it was MG and I saw the consultant last week. He was not to sure and thought it was hyperthyroidism caused by me overdosing on t3 - a hormone I take as I am hypothyroid. This is possible I suppose but before the addisons was diagnosed the t3 was blamed for my symptoms, so I need to be proved to that it is not MG and that it is t3 excess.

So, sorry for long preamble, what I would like to know is how one can tell the difference. When I saw the consultant I was pretty stressed which meant that my arms and legs were very weak, lips were not working and I could not hold my head up, and consultant implied that it was too extreme to be MG.

I am awaiting blood test results but I rarely show up with antibodies for things I do have and do have antibodies for things I don't have! I know that some folks do not have positive antibodies. I am going to have emg tests but have not been able to find out if these tests would be able to differentiate between MG weakness and thyrotoxic weakness. Does anyone know? The blood test might prove, if it is positive, that it is a definite MG diagnosis, but in case I do not get this I would like proof that it is one or the other....

Are there any other things that could help me be absolutely sure which one is causing my problems.... I do not want it to be a new illness and if it is excess t3 then I will have to cut this down which will cause other problems, but I do not want to be 'fobbed off' again by consultants.

Thanks for reading! Any comments really appreciated.

Many thanks, MrsC